Do you have a lot of similar components in your model? While I am able to open and orbit much larger models, I have a problem with one small 8Mb. model. It contains (among other things) about 190 components (a pine tree), each uniquely rotated and scaled, Each instance contains sub components (3,000 in the model) also scaled. each of the 3,000 instances contains 180 entities, including textures. The model orbits with difficulty, and fails to render. Attached is a SU export of the model.Temp00.png